Fabricated wheel and blade attachments



March 1963 w. s. CASTLE ETAL 3,081,021

FABRICATED WHEEL AND BLADE ATTACHMENTS Filed 0012. 14, 1959 5Sheets-Sheet 1 INVENTORS' ZZZ A fizz/m 542M: 5. 00 B e/air z? z/$ MZW-wATTORNEY March 12, 1963 w. s. CASTLE ETAL 3,081,021

FABRICATED WHEEL AND BLADE ATTACHMENTS Filed Oct. 14, 1959 5Sheets-Sheet 2 ATTORNEY W. S. CASTLE ETAL March 12, 1963 FABRICATEDWHEEL AND BLADE ATTACHMENTS 3 Sheets-Sheet 3 Filed Oct. 14, 1959 UnitedStates PatentOfiFice 3,081,021 Patented Mar. 12, 1963 3,081,021FABRICATED WHEEL AND BLADE ATTACHMENTS William S. Castle, Speedway, andJohn B. Minnicli, Indianapolis, Ind., assignors to General MotorsCorporation, Detroit, Micl1., a corporation of Delaware Filed Oct. 14,1959, Ser. No. 846,505 2 Claims. (Cl. 230-134) This invention relates toa rotor assembly.

More particularly, it is an object of-this invention to provide a lowcost fabricated rotor assembly that is easy to assemble and disassemble.

1 Other objects, features ad advantages will become apparent uponreference to the succeeding detailed description and to the drawingsillustrating the preferred embodiments of the invention, wherein:

FIGURE 1 is a front elevational view with parts broken away and insection of one embodiment of the invention,

FIGURE 2 is an enlarged plan view with parts broken away and in sectiontaken on a plane indicated by and viewed in the direction of the arrows22 of FIG- URE 1,

FIGURE 3 is a cross-sectional view taken on a plane indicated by andviewed in the direction of arrows 3--3 of FIGURE 1,

FIGURE 4 is a cross-sectional view taken on a plane indicated by andviewed in the direction of the arrows 4-4 of FIGURE 1,

FIGURE 5 is an enlarged exploded perspective view of a detail,

FIGURE 6 is a front elevational view of another embodiment of theinvention,

FIGURE 7 is a cross-sectional view taken on a plane indicated by andviewed in the direction of arrows 77 of FIGURE 6, and

FIGURE 8 is a cross-sectional view taken on a plane indicated and viewedin the direction of arrows 8-8 of FIGURE 6.

Referring to the drawings and more particularly to FIGURE 1, there isshown therein an arcuate portion of an axial flow type rotor assembly 12incorporating one embodiment of this invention, the assembly including anumber of blades 14 adapted to be secured to a rotor 16 and spacedequally circumferentially therearound by a number of spacers 18.

Referring more particularly to the details, each of the blades 14 ispreferably machined from bar stock in the shape of an airfoil as shownso as to provide an enlarged inclined root or base portion 20 integraltherewith at the radially inner end 22 thereof.

As seen more clearly in FIGURES 2 and 5, each of the root portions 20 isundercut or recessed at opposite sides 24 and 26 by suitable millingoperations to provide radially, axially and circumferentially spacedtang portions 28 and 30 depending from the blade. The milling operationsand spacing also provide on opposite sides of the root of shelf portion32 (FIGURE 1), 34 at one edge formed integral with the upper edge of thetang portion 28 or 39 to together constitute a blade platform 36inclined with respect to the axis so as to direct the how of airthereover in the most advantageous and efiicient direction. a

The radial spacing of the tang portions provides a line of connectionand support of the blades to the rotor at the same inclination as theblade platform and the air flowing thereover thus providing a moredurable connection. The tang portions are also circumferentially spacedfrom each other so as to be positioned directly below the adjacentcurved portion of the airfoil, which is supported thereby, to give thebest distribution of stress.

The tang portions are further axially spaced with respect to each otherfor cooperation with two axially spaced parallel annular sheet metalplates 38 and 40 secured together at 42 by suitable means to comprisethe rot-or wheel 16, each of the tang portions being circumferentiallycut at its inner end to provide a radial slot 42, 44 for receiving thediscs 38 and 40 therein. The tang portions are adapted to be secured tothe discs by the insertion of rivets 46, 48 in the holes 50, 52 and 54,56, respectively. It will be seen therefore that the overallconfiguration of each blade root matches the curvature of the blade fromwhich the root depends therefore providing for a minimum of metal whilegiving optimum stress distribution and support to the blade. v

Each of the blades or airfoil assemblies is adapted to becircumferentially spaced from each other by spacer means 18 comprisingtwo axially spaced radial sheet metal plates 60 and 62 axially flangedat 6'4 and 66 for cooperation with a top sheet metal plate 68constituting a platform inclined at the same angle as the blade platform36 for cooperation therewith. The plates 60 and 62, as well as platform68, extend circumferentially for the entire desired spacing betweenblades so as to not only constitute a continuous streamlined surface toreduce friction, etc., losses, but also an air or gas seal to reduce toa minimum the passage of air or gas between the blades in any directionor path other than over the platforms 36 and 68. The leg plates 60 and62 are radially spaced for the same purpose as are tang portions 28, 30,and are axially spaced so as to fit Within the opening defined by theaxial distance between rotor discs 38 and 40 to which they are adaptedto be rive-ted as shown.

The assembly of this embodiment of the invention is believed to be clearfrom the drawings; however, a brief resume will be given. The tangportions 28 and 30 of the airfoils are dropped into place over the rotordiscs 38 and 40 so as to straddle the same with the holes 50, 52 and54,- 56 therein being aligned, and the rivets 44, 46 are insertedtherein. The spacer means 58 which has been preassembled by riveting theleg plates 60 and 62 to the platform 68 at 69 and 70, is then dropped inplace between the discs 38 and 40 with the holes 71 and 72 thereinaligned with the holes 74 and 76 in the discs, and the edge of theplatform 68 abutting the adjacent edge of the platform 36, and therivets 78 are then inserted therein. The next circumferentially adjacentblade and root is then riveted to the rotor wheel, with the connectionof the spacer means following, etc., until the entire rotor isassembled. Thus, a low weight, high strength, economically fabricatedrotor assembly is provided. The assembly may be disassembled by ashearing oif of the rivet heads and a reversal of the assemblyprocedure.

FIGURES 6 to 8 illustrate another embodiment of the inven ion, thisembodiment differing from the FIGURES l to 5 embodiment primarily in theconstruction of the blade root to accommodate connection thereof to twonon-parallel axially spaced sheet metal annular plates or discs 80 and82 comprising the rotor wheel.

In this embodiment, the converging discs 80 and 82 are each provided attheir peripheries with radially extend-.

ing axially spaced portions 84 and 86 parallel to each other and adaptedto be received within two axially spaced radial slots 88 and 90circumferentially cut in the depending tank 92 of the root or base 94 ofa blade 96. The blade or airfoil 96 is constructed in a manner similarto that of FIGURES 1 to 5 embodiment, i.e., machined from bar stock inthe shape of an airfoil while providing an enlarged root portion. Theroot portion is milled or recessed both at the upstream and thedownstream sides of the assembly to provide circumferentially spacedstruts 98 and 100, respectively, for distributing the spar-p21 stressfrom the blades to the connection to the discs. The I trimming away ofthe metal between strutsreducing'the weight of the root to a low value.The milling thus provides a root having a centrally depending slottedradial tank portion 92 with substantially axially extending shelfportions 102 and 104 together constituting a blade platform 1% inclinedas shown in the same direction and for the same purpose as the FIGURES 1to embodiment.

The spacer means 108 is substantially the same as that of FIGURE 4,comprising two sheet metal radial plates 110 and 112 axially spaced by aspacer 113, flanged at 114 and 116 and riveted to an inclined platform113 at 129 and 122, the axial spacing of the plates being such as topermit straddling of the two discs 80 and 82 by the plates, and rivetingthem together.

The assembly of this embodiment is substantially the same as the FIGURES1-5 embodiments, i.e., the blade and tang 92 are dropped into place overthe discs 80' and 82 and riveted thereto by the insertion of the rivets124 into the holes provided in the tank and discs. The preassembledspacer means 108 is then placed over the two discs as shown in FIGURE 8,and riveted thereto by rivets 126 being inserted in the holes providedin the discs, a spacer member 113 being positioned therebetween. Thenext circumferentially adjacent blade assembly is then inserted in placeand riveted, followed by a spacer means, and so on around thecircumference of the rotor wheel until the entire rotor is assembled.The assembly may be also easily disassembled by shearing off the rivets,and reversing the assembly operation.

Thus, a rotor assembly of very light weight and great strength isprovided for easy and economical fabrication.

While the preferred embodiments of the invention have been illustratedin FIGURES 1 to 8, it will be clear that many modifications can be madethereto by those skilled in the art to which this invention pertainswithout departing from the scope of the invention.

We claim:

1. A lightweight rotor blade assembly comprising a rotor, a plurality ofthin arcuately curved airfoil type blades adapted to be secured to saidrotor at the periphery thereof, spacer means for circumferentiallyspacing said blades and spanning the gap therebetween, and means forsecuring said blades and spacer means and said rotor rigidly together,said rotor comprising a number of annular axially spaced plates, each ofsaid blades having an enlarged root integral with and beneath said bladeand having an overall configuration substantially matching the curvatureof said blade, each of said roots having axially and circumferentiallyspaced tang portions depending radially beneath and being substantiallyaligned with the leading and trailing edges of said blade, each of saidtang portions being slotted to receive a rotor plate therein, said roothaving other portions extending between and connecting said tangportions to support all portions of said blade.

2. A rotor blade assembly as in claim 1, wherein said other portionsextend from each of said tang portions each in a different direction,said other portions being recessed, said recesses being axially andcircumferentially spaced from each other and each forming a shelfportion-integral with each other and said tang portions, said tangportions and shelf portions together constituting a platform for saidblade, said tang portions depending beneath diametrically opposite edgeportions of said platform.

References Cited in the file of this patent FOREIGN PATENTS 528,031France Oct. 6, 1921 652,099 Great Britain Apr. 18, 1951 718,139 GreatBritain Nov. 10, 724,281 Great Britain Feb. 16, 1955 742,194 GreatBritain Dec. 21, 1955 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No 3,081,021 March 12, 1963 William 5. Castle et al.

- It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column l line 14, for "ad" read and for "of" read a tang line 59, column3, line 21, for "tank" read Signed and sealed this 8th day of October1963.,

(SEAL) Attest:

' EDWI I ERNEST w. SWIDER REYNOLDS- Attesting Officer Ac t i ngCommissioner of Patents

1. A LIGHTWEIGHT ROTOR BLADE ASSEMBLY COMPRISING A ROTOR, A PLURALITY OF THIN ARCUATELY CURVED AIRFOIL TYPE BLADES ADAPTED TO BE SECURED TO SAID ROTOR AT THE PERIPHERY THEREOF, SPACER MEANS FOR CIRCUMFERENTIALLY SPACING SAID BLADES AND SPANNING THE GAP THEREBETWEEN, AND MEANS FOR SECURING SAID BLADES AND SPACER MEANS AND SAID ROTOR RIGIDLY TOGETHER, SAID ROTOR COMPRISING A NUMBER OF ANNULAR AXIALLY SPACED PLATES, EACH OF SAID BLADES HAVING AN ENLARGED ROOT INTEGRAL WITH AND BENEATH SAID BLADE AND HAVING AN OVERALL CONFIGURATION SUBSTANTIALLY MATCHING THE CURVATURE OF SAID BLADE, EACH OF SAID ROOTS HAVING AXIALLY AND CIRCUMFERENTIALLY SPACED TANG PORTIONS DEPENDING RADIALLY BENEATH AND BEING SUBSTANTIALLY ALIGNED WITH THE LEADING AND TRAILING EDGES OF SAID BLADE, EACH OF SAID TANG PORTIONS BEING SLOTTED TO RECEIVE A ROTOR PLATE THEREIN, SAID ROOT HAVING OTHER PORTIONS EXTENDING BETWEEN AND CONNECTING SAID TANG PORTIONS TO SUPPORT ALL PORTIONS OF SAID BLADE. 